Integrated circuits (ICs) including, for example, a System on a Chip (SoC), can include, for example, a large number (e.g., millions, billions) of transistors on a chip. These transistors may differ in structure or use, having different operational characteristics.
Chips have become increasingly vulnerable to compromise, tampering and/or counterfeiting from unauthorized third parties. For example, Bhunia, Swamp et al., “Hardware Trojan Attacks: Threat Analysis and Countermeasures,” Proceedings of the IEEE, Vol. 102, No. 8, August 2014, states that “hardware Trojan attacks . . . in the form of malicious modifications of electronic hardware at different stages of its life cycle, pose major security concerns in the electronics industry. An adversary can mount such an attack with an objective to cause operational failure or to leak secret information from inside a chip.” As a result, chip security has become increasingly important. As noted in Suh, G. Edward, et al., “Physical Unclonable Functions for Device Authentication and Secret Key Generation,” Proceedings of the 44th annual Design Automation Conference, A C M, 2007, attempts to provide chip security include the use of physical unclonable functions (PUFs), which are “circuit primitives that extract secrets from physical characteristics of integrated circuits (ICs) . . . [and] exploit inherent delay characteristics of wires and transistors that differ from chip to chip.”
However, known methods of providing chip security, including software-based security, are prone to malicious attack, and are difficult to implement. Accordingly, more secure alternative methods for providing chip security that are easier to implement are needed.